Question

Why is photo electron current proportional to the intensity of incident radiation

Answer 1

We know that Flow of charges is called current. Photo current is the current which flows due to the flow of photoelectrons.

Now, coming to the photoeectric effect. It is a phenomenon in which when a light is incident on a metal surface then an electron comes out of the surface.

Now, earlier it was thought that if we increase the intensity of the incident light , then more photo electrons will be emitted and hence more current will flow. Due to this it was said that intensity and photo current are directly proportional to each other.

Actually what happens is that there is no role of intensity and it is the value of energy of incident radiation that decides the number of photoelectrons emitted.

I hope this answer was helpful and made your concept clear.

Thanks !